Author
Topic: Bolt probe for bulldog? (Read 1418 times)

I have been tinkering around with the bulldog.357 and currently have opened up the ports to 9/32” and have been able to achieve a maximum speed of 860 FPS and a slowest of 842 FPS with 153gr cast bullets. This is a substantial improvement from stock but there isn’t a lot more that I can do with the platform without sending it off to a professional. That being said, has anyone tried probing the bolt yet? Using cast bullets it should increase the speed slightly. I was thinking about ordering another bolt just to try and see what is or isn’t gained.

Any suggestions on length and width of such probe?

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Clarksville, Tennessee

"It is good that war is so terrible; for we should grow too fond of it." GEN Robert E. Lee

As you know, all of the WAR models have retractable probes. They take some getting used to, but after 10,000+ rounds, I don't even think about it. All said and done, 860 FPS out of a .357 Bulldog is pretty darn good based on what I've read on the forums.

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Roswell, New Mexico

Alan

I have an Omega compressor. If you're a fellow Guild member, and you pass through Roswell, NM, I'll fill your portable tank as a courtesy.

You can pick up 20-30fps by removing the poppet spring. Just have to point the gun up if filling from 0psi. I have an improved air valve in mine from JSAR that took my fpe up to 330+ fpe with more possible. They will be selling them shortly for $165. Installation is easy, just remove air tube, and current poppet and spring, and the new air valve just threads between the air tube and the receiver. Regards, Tom

Thanks for the information. I have already removed the spring and it did increase the velocity a bit. Im not looking to purchase anything right now. Just tossing around ideas without tossing around money. Not that it won’t be an option in the future but for now I am quite happy with little increases that are achievable without a machine shop.

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Clarksville, Tennessee

"It is good that war is so terrible; for we should grow too fond of it." GEN Robert E. Lee

The probe seems to have made a slight increase in speed but nothing dramatic. 5 shots from 3k with 150gr .358 went from 868-876-880-872-859. These speeds don’t seem impressive but with a 150gr bullet sized to .358 it’s fair to say that a smaller diameter bullet would greatly increase the numbers. When I first received the gun new the max was around 750 for the 150gr.

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Clarksville, Tennessee

"It is good that war is so terrible; for we should grow too fond of it." GEN Robert E. Lee

I went through the bulldog today and discovered the reason as to why a probe that clears the magazine is only a minor, and in some cases, zero improvement. It is apparent that if the probe is able to clear the magazine then the pellet, or bullet isn’t pushed far enough into the chamber and actually blocks a portion of the port on the barrel. After realizing this by using a small mirror and a light I went about ways to make it work. I found that by pulling back on the cocking arm while inserting the magazine it not only cleared the magazine but also seated the bullet far enough forward to clear the port.

After another string I found that the speed increased to 899-886-870-862-849 for a max speed increase of 19fps. It just goes to show that with a little patience and a bit of attention to detail, what one can accomplish!

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Clarksville, Tennessee

"It is good that war is so terrible; for we should grow too fond of it." GEN Robert E. Lee